The episode title is a reference to the early Edison movie The Great Train Robbery (1903), which demonstrated many of the techniques of telling a story with film.
After Barney shows Andy his intercom system, Andy refers to him as "Mr. Marconi." Guglielmo Marconi was an Italian inventor and electrical engineer, known for his pioneering work on long-distance radio transmission.
When leaving the sheriff's office, Andy keys up the intercom and says, "This is Mercury Control, over, a-okay and out." The Mercury Control Center provided control and coordination of all activities associated with the NASA's Project Mercury flight operation, which was the manned spaceflight program for the United States from 1958-1963. This episode aired on February 25. 1963.
Barney's trick with the camera was not a failed experiment, as he thought. It actually proves Jimmy's innocence. Consider the facts: 1, Jimmy only had a key to the front door and therefore, could not come in through the back door. 2, Barney's hidden camera was set up to go off only when the front door was opened. 3, None of the doors were forced and the camera was not tampered with. 4, There were no pictures in the camera except the one Barney took of himself while setting it up. So, whoever came in did not use the front door, which was the only way Jimmy could come in. Thus, the thief could not be Jimmy. CORRECTION: This idea completely falls apart when one considers the camera only takes single pictures and was not reset after Barney accidentally sprung the trap.
Barney is on the phone flirting with Juanita early in the episode. Later, Gomer said Barney should get copies of his photo and give one to Thelma Lou.